Key terms & definitions

A small fortified defensive position, often containing artillery.

A reaction in which oxidation and reduction occur together because electrons are transferred between particles.

A reaction in which oxidation and reduction occur together, with electrons transferred between particles.

Reworking a draft to improve its meaning, organisation or expression.

A period of widespread fear that communists were infiltrating American institutions and threatening the country.

An increase in the observed wavelength of light compared with the wavelength at which it was emitted.

An increase in the wavelength of light from distant galaxies, providing evidence that the universe is expanding.

An expanded, very massive star that can later undergo a supernova.

The organised campaign of Bolshevik political repression launched in 1918, involving arrests, executions and intimidation of suspected enemies.

A popular newspaper with a red masthead, such as the Daily Mirror.

Using less material or fewer products in the first place, reducing demand for raw materials and energy.

Using fewer materials, less energy or fewer other resources when making and using products.

A substance that causes another substance to be reduced and is itself oxidised.

A substance that removes oxygen from another substance, causing it to be reduced.

A sugar, such as glucose, lactose or maltose, that gives a positive result with Benedict’s solution when heated.

A sugar that gives a positive result when heated with Benedict’s solution. Examples include glucose, lactose and maltose.

The gain of electrons by a substance.

The gain of electrons by a particle.

Heating a liquid so that water evaporates, decreasing its volume and concentrating its flavour.

Using less material or fewer products, so fewer resources are needed and less waste is generated.

An approach that explains a complex problem by breaking it down into simpler components or focusing on a limited mechanism.

A sauce thickened by heating it so that some of its water evaporates.

The loss of a job because the business no longer needs that role.

The provision of additional connections or components so that alternatives are available if something fails.

The loss of a job because an employer no longer needs that role.

A switch with contacts operated by a nearby magnetic field.

A local official who supervised agricultural work and ensured that peasants fulfilled their obligations to the lord.

Replacing or renewing the outer surface of a building's walls.

Evidence about a candidate’s abilities and suitability provided by someone who knows them in a professional capacity.

The quantity used as the basis of a percentage calculation, representing 100%.